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Finding the Fourth Proportional to 702.31, 969.20 and 391.81

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Solution

The fourth proportional to 702.31, 969.20 and 391.81 is: 540.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    702.31 : 969.20 = 391.81 : x
  2. Step 2: Convert to fraction form
    702.31/969.20 = 391.81/x
  3. Step 3: Cross multiply
    702.31x = 969.20 × 391.81
  4. Step 4: Simplify right side
    702.31x = 379,742.25
  5. Step 5: Solve for x
    x = 379,742.25/702.31
  6. Step 6: Final answer
    x = 540.70

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.